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1.
Nat Commun ; 15(1): 3485, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38664427

RESUMEN

Spider silk exhibits an excellent combination of high strength and toughness, which originates from the hierarchical self-assembled structure of spidroin during fiber spinning. In this work, superfine nanofibrils are established in polyelectrolyte artificial spider silk by optimizing the flexibility of polymer chains, which exhibits combination of breaking strength and toughness ranging from 1.83 GPa and 238 MJ m-3 to 0.53 GPa and 700 MJ m-3, respectively. This is achieved by introducing ions to control the dissociation of polymer chains and evaporation-induced self-assembly under external stress. In addition, the artificial spider silk possesses thermally-driven supercontraction ability. This work provides inspiration for the design of high-performance fiber materials.


Asunto(s)
Nanofibras , Polielectrolitos , Seda , Arañas , Animales , Nanofibras/química , Arañas/química , Seda/química , Polielectrolitos/química , Resistencia a la Tracción , Músculos , Materiales Biomiméticos/química
2.
Natl Sci Rev ; 10(10): nwad191, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37671322

RESUMEN

Perfluorooctanoic acid (PFOA), a representative of per/polyfluorinated alkyl substances, has become a persistent water pollutant of widespread concern due to its biological toxicity and refractory property. In this work, we design and synthesize two porous aromatic frameworks (PAF) of PAF-CF3 and PAF-C2F5 using fluorine-containing alkyl based monomers in tetrahedral geometry. Both PAFs exhibit nanosized pores (∼1.0 nm) of high surface areas (over 800 m2 g-1) and good fluorophilicity. Remarkable adsorption capacity (˃740 mg g-1) and superior efficiency (˃24 g mg-1 h-1) are achieved toward the removal of PFOA with 1 µg L-1 concentration owing to unique C-F···F-C interactions. In particular, PAF-CF3 and PAF-C2F5 are able to reduce the PFOA concentration in water to 37.9 ng L-1 and 43.3 ng L-1, below EPA regulations (70 ng L-1). The reusability and high efficiency give both PAFs a great potential for sewage treatment.

3.
Macromol Rapid Commun ; 44(23): e2300318, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37572085

RESUMEN

It is an urgent need to develop efficient solid state cooling technologies and materials with high cycle life. Poly-p-phenylene benzodioxole (PBO) is a high performance fiber with excellent mechanical properties. In this work, for the first time, elasto- and twistocaloric cooling of PBO fibers by stretching and twisting of the PBO fiber bundles is reported. The cooling temperature reaches -0.4 and -1.3 K, for fiber stretching and twisting, respectively. A self-coiled PBO fiber achieves maximum cooling of -3.7 K upon stretching by 35% strain, with an exceptionally high cycle life of 200 000 times. During the twisting of the PBO fibers, reversible changes in the intensity of the diffraction peaks in X-ray diffraction patterns are observed. A strain-sensitive color change application is realized by coating a self-coiled PBO fiber with liquid crystallite dyes. This work provides new perspectives for PBO fibers as a high cycle-life solid-state refrigeration material.


Asunto(s)
Cicloparafinas , Compuestos Heterocíclicos , Frío , Temperatura , Benzodioxoles
4.
Adv Mater ; 35(32): e2212112, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37326574

RESUMEN

The axial orientation of molecular chains always results in an increase in fiber strength and a decrease in toughness. Here, taking inspiration from the skin structure, artificial spider silk with a buckled sheath-core structure is developed, with mechanical strength and toughness reaching 1.61 GPa and 466 MJ m-3 , respectively, exceeding those of Caerostris darwini silk. The buckled structure is achieved by nano-pulley combing of polyrotaxane hydrogel fibers through cyclic stretch-release training, which exhibits axial alignment of the polymer chains in the fiber core and buckling in the fiber sheath. The artificial spider silk also exhibits excellent supercontraction behavior, achieving a work capacity of 1.89 kJ kg-1 , and an actuation stroke of 82%. This work provides a new strategy for designing high-performance and intelligent fiber materials.


Asunto(s)
Seda , Arañas , Animales , Seda/química , Estrés Mecánico
5.
Macromol Rapid Commun ; 44(23): e2300275, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37344253

RESUMEN

The twistocaloric effect is attributed to the change in entropy of the material driven by torsional stress. It is responsible for the torsional refrigeration of fiber materials that has been widely exploited as one of the solid-state cooling techniques with high efficiency and low volume change rate. The lack of theories and mathematical models of twistocaloric effect, however, limits broad applications of torsional refrigeration. In this work, a twistocaloric model is established to capture the relationship between twist density and temperature variation of natural rubber fibers and thermoplastic elastomer yarns. An experimental setup consisting torsion actuator and torque sensor coupled with a temperature measurement system is built to validate the model. Using the Maxwell relationship, twistocaloric coefficient is measured by quantifying the thermal effect induced by torsion under shear strain. The experimental characterization of the twistocaloric effect in natural rubber fiber and thermoplastic elastomer yarn are consistent with the theoretical predictions.


Asunto(s)
Elastómeros , Goma , Temperatura , Frío , Modelos Teóricos
6.
Angew Chem Int Ed Engl ; 62(29): e202306261, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37222120

RESUMEN

The development of efficient catalyst for selective oxidation of hydrocarbon to functional compounds remains a challenge. Herein, mesoporous Co3 O4 (mCo3 O4 -350) showed excellent catalytic activity for selective oxidation of aromatic-alkanes, especially for oxidation of ethylbenzene with a conversion of 42 % and selectivity of 90 % for acetophenone at 120 °C. Notably, mCo3 O4 presented a unique catalytic path of direct oxidation of aromatic-alkanes to aromatic ketones rather than the conventional stepwise oxidation to alcohols and then to ketones. Density functional theory calculations revealed that oxygen vacancies in mCo3 O4 activate around Co atoms, causing electronic state change from Co3+ (Oh) →Co2+ (Oh) . Co2+ (Oh) has great attraction to ethylbenzene, and weak interaction with O2 , which provide insufficient O2 for gradual oxidation of phenylethanol to acetophenone. Combined with high energy barrier for forming phenylethanol, the direct oxidation path from ethylbenzene to acetophenone is kinetically favorable on mCo3 O4 , sharply contrasted to non-selective oxidation of ethylbenzene on commercial Co3 O4 .

7.
Small ; 19(35): e2301578, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37105762

RESUMEN

The development of coordination polymers with π-d conjugation (CCPs) provides ide prospects for exploring the next generation of environmental-friendliness energy storage systems. Herein, the synthesis, experimental characterizations, and Na-ion storage mechanism of π-d CCPs with multiple-active sites are reported, which use quinone-fused aza-phenazine (AP) and aza-phenazin (AP) as the organic ligands coordinated with the metal center (Ni2+ ). Among them, NiQAP as the cathode material exhibits impressive electrochemical properties applied in sodium-ion batteries (SIBs), including the high initial/stable discharge specific capacities (180.0/225.6 mAh g-1 ) at 0.05 A g-1 , a long-term cycle stability up to 10,000 cycles at 1.0 A g-1 with a high reversible capacity of 100.1 mAh g-1 , and good rate capability of 99.6 mAh g-1 even at 5.0 A g-1 . Moreover, the Na-ion storage mechanism of NiQAP is also performed by the density functional theory (DFT) calculation, showing multiple-active sites of C≐O and C≐N (in the quinone and phenazine structure) and NiO4 (in the coordination unit) for Na-ion storage. These results highlight the importance of organic electrode material with the coordination units and provide a foundation for further studying the CCPs with multiple active sites for energy storage systems.

8.
Metabolites ; 12(10)2022 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-36295803

RESUMEN

For precise delineation of glioma extent, amino acid PET is superior to conventional MR imaging. Since metabolic MR sequences such as chemical exchange saturation transfer (CEST) imaging and MR spectroscopy (MRS) were developed, we aimed to evaluate the diagnostic accuracy of combined CEST and MRS to predict glioma infiltration. Eighteen glioma patients of different tumor grades were enrolled in this study; 18F-fluoroethyltyrosine (FET)-PET, amide proton transfer CEST at 7 Tesla(T), MRS and conventional MR at 3T were conducted preoperatively. Multi modalities and their association were evaluated using Pearson correlation analysis patient-wise and voxel-wise. Both CEST (R = 0.736, p < 0.001) and MRS (R = 0.495, p = 0.037) correlated with FET-PET, while the correlation between CEST and MRS was weaker. In subgroup analysis, APT values were significantly higher in high grade glioma (3.923 ± 1.239) and IDH wildtype group (3.932 ± 1.264) than low grade glioma (3.317 ± 0.868, p < 0.001) or IDH mutant group (3.358 ± 0.847, p < 0.001). Using high FET uptake as the standard, the CEST/MRS combination (AUC, 95% CI: 0.910, 0.907−0.913) predicted tumor infiltration better than CEST (0.812, 0.808−0.815) or MRS (0.888, 0.885−0.891) alone, consistent with contrast-enhancing and T2-hyperintense areas. Probability maps of tumor presence constructed from the CEST/MRS combination were preliminarily verified by multi-region biopsies. The combination of 7T CEST/MRS might serve as a promising non-radioactive alternative to delineate glioma infiltration, thus reshaping the guidance for tumor resection and irradiation.

9.
ACS Appl Mater Interfaces ; 14(24): 27775-27790, 2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35679591

RESUMEN

Water-soluble captopril-capped atomically precise Pd nanoclusters (Pd17Capt8 NCs: 1.3 ± 0.5 nm) produced by a simple chemical reduction were supported on preprepared hybrid Co3Al-layered double hydroxide/reduced graphene oxide (Co3Al-LDH/rGO) by a pH-adjusted electrostatic adsorption strategy followed by proper calcinations, giving a series of novel catalysts x-PdNCs/CoAl(O)/rGO-T (x (Pd loading) = 0.09, 0.17, 0.43 wt % (ICP), T = 230, 250, 280, 300, 320 °C). The characterization results show that the as-obtained catalysts possess the hierarchical nanosheet array morphology. Pd NCs with a size of ∼1.3 to 1.8 nm are highly distributed at the edge sites of the CoAl(O) nanosheets. All of the x-PdNCs/CoAl(O)/rGO-T catalysts show superior catalytic efficiency for the conversion of 4-nitrophenol to 4-aminophenol, particularly 0.17-PdNCs/CoAl(O)/rGO-300 possesses the highest performance with a turnover frequency (TOF) of 30 042 h-1, which is the highest among the reported Pd-based catalysts so far. The superior activity of 0.17-PdNCs/CoAl(O)/rGO-300 can be owing to ultrafine Pd NCs with a clean surface, the strongest PdNCs-Co2+-OH(LDH)-rGO three-phase synergy, and the much improved adsorption of the substrate via π-π stacking upon nanosheet array morphology. Meanwhile, 0.17-PdNCs/CoAl(O)/rGO-300 exhibits excellent catalytic activities for various nitroarenes and anionic azo dyes as well as good reusability with the complete reduction of 4-nitrophenol (4-NP) within 90 s after 10 successive runs. The present work provides not only a simple and convenient strategy for the synthesis of clean, efficient, and environmentally friendly supported metal nanocluster catalysts but also a new idea for the efficient catalytic degradation of environmental pollutants.

10.
ACS Appl Mater Interfaces ; 14(21): 24265-24280, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35604135

RESUMEN

A series of Co-doped ternary CuxCo3-xAl-layered double hydroxide (LDH)/rGO nanosheet array hybrids (x = 0.5, 1.0, 1.5, and 2.0) were successfully prepared using the preconditioned pH value aqueous-phase coprecipitation strategy. The CuxCo3-xAl-LDH/rGO hybrids are featured as hexagonal CuCoAl-LDH nanosheets in situ anchoring onto both sides of the rGO surface in an ab-plane vertically interlaced growth pattern. The CuxCo3-xAl-LDH/rGO hybrids show excellent activity for the complete conversion of 4-nitrophenol to 4-aminophenol, especially Cu1.5Co1.5Al-LDH/rGO with the highest kapp value of 49.2 × 10-3 s-1 and TOF of 232.8 h-1, clearly higher than most copper-containing samples in the literature and even some precious ones. Thermodynamic analysis was carried out, and the values of Ea, ΔH#, ΔS#, and ΔG# were estimated. The best activity of Cu1.5Co1.5Al-LDH/rGO can be mainly ascribed to the in situ-formed ultrafine Cu2O NPs (∼4.3 nm) along with a small amount of Cu0 species, the electron transfer effect induced by atomically dispersed Co2+ species leading to the formation of electron-rich Cu species along with the Co2+/Co3+ redox couple, the strong Cu2O-CuCoAl-LDH-rGO synergy upon the nanosheet array morphology with a high surface area and pore volume, and enhanced adsorption of reactants upon π-π stacking via an rGO layer. Meanwhile, the Cu1.5Co1.5Al-LDH/rGO exhibits an excellent universality and good cycling stability for 10 continuous runs. The Cu1.5Co1.5Al-LDH/rGO also shows superior efficiency in the catalytic reduction of 4-NP solution with a high concentration (20 mM) and displays excellent reduction performance in the fixed-bed test, implying the potential applications of the current Co-doped hierarchical ternary Cu-based LDH/rGO hybrids in the continuous treatment of practical wastewater.

11.
Macromol Rapid Commun ; 43(14): e2100923, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35134260

RESUMEN

The design of porous noble metal catalysts holds great promise in various electrocatalytic applications. However, it is still a challenge to improve the durability performance through constructing stable framework. Here, an interface and charge induced strategy is developed to synthesize large-sized continuous reduced graphene oxide@mesoporous platinum (denoted as rGO@mPt) sheets under kinetic control by molecular self-assembly design. Graphene oxide (GO) is a promising large-sized growth interface for platinum. Cationic surfactant dioctadecyldimethylammonium chloride bridges the negatively charged GO and platinum precursors, while creating interconnected mesopores. The successful synthesis of rGO@mPt sheets relies on proper kinetic control, which is achieved by controlling pH, temperature, and the complexation of bromide ions. rGO@mPt sheets present strong crystallinity with a pure face-centered cubic Pt phase. Worm-like mesostructures with an average pore size of 2.2 nm exist throughout the sheets. rGO@mPt sheets possess both stable framework and abundant active sites, which markedly improve the durability on methanol oxidation reaction while maintaining relatively good catalytic activity. Long-term stability test shows a slight loss of 1.2% activity after 250 cycles. Amperometric i-t curves reveal the mass current three times higher compared to commercial Pt/C at 3000 s.


Asunto(s)
Grafito , Platino (Metal) , Catálisis , Grafito/química , Oxidación-Reducción , Platino (Metal)/química
12.
Neuropsychologia ; 165: 108112, 2022 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-34890691

RESUMEN

Although mate choice is crucial for adults, its neural basis remains elusive. In the current study, we combined the functional near-infrared spectroscopy (fNIRS)-based hyperscanning and speed-dating to investigate the inter-brain mechanism of mate choice. Each participant was paired with two opposite-sex partners (participants) in separate speed-dating sessions and was asked to decide whether to engage in a further relationship with the paired partner after each session. The physical attraction of the daters was rated by their partners at the beginning of the dating whereas the social attraction was rated after the dating. Interpersonal neural synchronization (INS) at the dorsolateral prefrontal cortex during speed-dating rather than reading task predicts the outcome of mate choice. Moreover, social attraction rather than physical attraction affects INS during speed-dating. These findings demonstrate for the first time that INS predicts the outcome of mate choice of interacting daters in ecologically valid settings during their initial romantic encounter.


Asunto(s)
Encéfalo , Relaciones Interpersonales , Adulto , Femenino , Humanos , Masculino
13.
Front Bioeng Biotechnol ; 9: 735714, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34869254

RESUMEN

Rapeseed meal (RSM) is a major by-product of oil extraction from rapeseed, consists mainly of proteins and phenolic compounds. The use of RSM as protein feedstock for microbial fermentation is always hampered by phenolic compounds, which have antioxidant property with health-promoting benefits but inhibit bacterial growth. However, there is still not any good process that simultaneously improve extraction efficiency of phenolic compounds with conversion efficiency of protein residue into microbial production. Here we established a two-step strategy including fungal pretreatment followed by extraction of phenolic compounds. This could not only increase extraction efficiency and antioxidant property of phenolic compounds by about 2-fold, but also improve conversion efficiency of protein residue into iturin A production by Bacillus amyloliquefaciens CX-20 by about 33%. The antioxidant and antibacterial activities of phenolic extracts were influenced by both total phenolic content and profile, while microbial feedstock value of residue was greatly improved because protein content was increased by ∼5% and phenolic content was decreased by ∼60%. Moreover, this two-step process resulted in isolating more proteins from RSM, bringing iturin A production to 1.95 g/L. In conclusion, high-value-added and graded utilization of phenolic extract and protein residue from RSM with zero waste is realized by a two-step strategy, which combines both benefits of fungal pretreatment and phenolic extraction procedures.

14.
Brain Cogn ; 151: 105738, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33915401

RESUMEN

Although tend-and-befriend is believed to be the dominant stress response in women, little is known regarding the effects of acute psychosocial stress on different dynamic social interactions. To measure these effects, 80 female participants were recruited, paired into the dyads, and instructed to complete cooperative and competitive key-pressing tasks after experiencing acute stress or a control condition. Each dyad of participants should press the key synchronously when the signal was presented in the cooperative task and as fast as possible in the competitive task. During the tasks, brain activities of prefrontal and right temporo-parietal areas were recorded from each dyad using functional near-infrared spectroscopy (fNIRS). The results showed that acute psychosocial stress evidently promoted competitive behavior, accompanied by increased interpersonal neural synchronization (INS) in the right dorsolateral prefrontal cortex. Despite the lack of a significant difference in the overall cooperation rate, the response time difference between two stressed participants markedly declined over time with more widespread INS in the prefrontal cortex, suggesting that there ensued cooperative improvement among stressed women. These findings behaviorally and neurologically revealed context-dependent response patterns to psychosocial stress in women during dynamic social interactions.


Asunto(s)
Conducta Cooperativa , Relaciones Interpersonales , Mapeo Encefálico , Femenino , Humanos , Corteza Prefrontal , Espectroscopía Infrarroja Corta , Estrés Psicológico
15.
Magn Reson Imaging ; 75: 141-148, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33129937

RESUMEN

PURPOSE: To compare the correlations among the R1ρ, R2, and R2* relaxation rates with liver iron concentration (LIC) in the assessment of rat liver iron content and explore the application potential of R1ρ in assessing liver iron content. METHODS: Iron dextran (dosage of 0, 25, 50, 100, and 200 mg/kg body weight) was injected into 35 male rats to increase the amount of iron storage in the liver. After one week, all rats were euthanized with isoflurane. A portion of the largest hepatic lobe was extracted to quantify the LIC by inductively coupled plasma, and the remaining liver tissue was stored in 4% buffered paraformaldehyde for 24 h before MRI. Spin-lock preparation with a RARE (rapid acquisition with relaxation enhancement) readout (9 different spin-lock times and 7 different spin-lock frequencies (FSLs)) and multi-echo UTE (ultrashort TE) pulses were developed to quantify R1ρ and R2 * on a Bruker 11.7 T MR system. For comparisons with R1ρ and R2*, R2 was acquired using the CPMG sequence. RESULTS: Mean R1ρ values displayed dispersion, with decrease in R1ρ at higher FSLs. Spearman's correlation analysis (two-tailed) indicated that the R1ρ values were significantly associated with LIC at FSL = 2000, 2500, and 3000 Hz (r = 0.365 and P = 0.031, r = 0.608 and P < 0.001, and r = 0.764 and P < 0.001, respectively), and were not significantly associated with LIC at FSL = 500, 1000, 1250, and 1500 Hz (all P > 0.05). R2 and R2* showed significant linear correlations with LIC (r = 0.787 and P < 0.001, and r = 0.859 and P < 0.001, respectively). Correlation analysis across R1ρ, R2, and R* also suggested that the correlation strength between R1ρ and R2 and between R1ρ and R* showed an increasing trend with increase in FSL. CONCLUSION: In this study, a strong association was observed between R1ρ and LIC at high FSLs further confirming previous findings. The results demonstrated that R1ρ at high FSL might serve as a complementary imaging biomarker for liver iron overload quantification.


Asunto(s)
Hierro/metabolismo , Hígado/diagnóstico por imagen , Hígado/metabolismo , Imagen por Resonancia Magnética , Animales , Biomarcadores/metabolismo , Pruebas Diagnósticas de Rutina , Masculino , Ratas
16.
Angew Chem Int Ed Engl ; 59(44): 19503-19509, 2020 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-32452613

RESUMEN

The development of noble-metal-free heterogeneous catalysts is promising for selective oxidation of aromatic alcohols; however, the relatively low conversion of non-noble metal catalysts under solvent-free atmospheric conditions hinders their industrial application. Now, a holey lamellar high entropy oxide (HEO) Co0.2 Ni0.2 Cu0.2 Mg0.2 Zn0.2 O material with mesoporous structure is prepared by an anchoring and merging process. The HEO has ultra-high catalytic activity for the solvent-free aerobic oxidation of benzyl alcohol. Up to 98 % conversion can be achieved in only 2 h, to our knowledge, the highest conversion of benzyl alcohol by oxidation to date. By regulating the catalytic reaction parameters, benzoic acid or benzaldehyde can be selectively optimized as the main product. Analytical characterizations and calculations provide a deeper insight into the catalysis mechanism, revealing abundant oxygen vacancies and holey lamellar framework contribute to the ultra-high catalytic activity.

17.
Nanomicro Lett ; 12(1): 14, 2019 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-34138086

RESUMEN

Manganese oxides are regarded as one of the most promising cathode materials in rechargeable aqueous Zn-ion batteries (ZIBs) because of the low price and high security. However, the practical application of Mn2O3 in ZIBs is still plagued by the low specific capacity and poor rate capability. Herein, highly crystalline Mn2O3 materials with interconnected mesostructures and controllable pore sizes are obtained via a ligand-assisted self-assembly process and used as high-performance electrode materials for reversible aqueous ZIBs. The coordination degree between Mn2+ and citric acid ligand plays a crucial role in the formation of the mesostructure, and the pore sizes can be easily tuned from 3.2 to 7.3 nm. Ascribed to the unique feature of nanoporous architectures, excellent zinc-storage performance can be achieved in ZIBs during charge/discharge processes. The Mn2O3 electrode exhibits high reversible capacity (233 mAh g-1 at 0.3 A g-1), superior rate capability (162 mAh g-1 retains at 3.08 A g-1) and remarkable cycling durability over 3000 cycles at a high current rate of 3.08 A g-1. Moreover, the corresponding electrode reaction mechanism is studied in depth according to a series of analytical methods. These results suggest that rational design of the nanoporous architecture for electrode materials can effectively improve the battery performance.

18.
Int J Mol Sci ; 17(10)2016 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-27727159

RESUMEN

Chondroitin sulfate (CS) plays important roles in the complement system. However, the CS structure is complicated due to different sources and the number and positions of sulfate groups. The objective of this study was to prepare different low molecular weight chondroitin sulfates (LMWCSs) and to investigate the biological activity in anti-complement capacity. A series of LMWCSs was prepared from different sources and characterized by ultraviolet-visible (UV) spectroscopy, high-performance liquid chromatography (HPLC), size exclusion chromatography-multiangle laser light scattering (SEC-MALLS) and nuclear magnetic resonance (NMR) spectroscopy. Hemolytic, anti-complement 3 deposition capacity and cell viability assays were carried out to investigate the biological activities in vitro. The results showed that LMWCS prepared from shark cartilage with the oxidative degradation method (LMWCS-S-O) had the best anti-complement capacity. LMWCS-S-O could inhibit the alternative pathway of the complement system and protect chondrocytes from cell death. The attenuating effect of LMWCS-S-O on Osteoarthritis (OA) was investigated by destabilization of the medial meniscus (DMM) model in vivo. Functional wind-up, histological and C5b-9 analyses were used to evaluate the treatment effect on the OA model. In vivo results showed that LMWCS-S-O could attenuate OA. LMWCS-S-O with a high content of ΔDi-2,6diS and ΔDi-6S could be used for attenuating OA through regulating the complement system.


Asunto(s)
Sulfatos de Condroitina/química , Sulfatos de Condroitina/farmacología , Osteoartritis , Animales , Supervivencia Celular/efectos de los fármacos , Condrocitos/efectos de los fármacos , Sulfatos de Condroitina/uso terapéutico , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos C57BL , Peso Molecular , Osteoartritis/tratamiento farmacológico , Distribución Aleatoria , Resultado del Tratamiento
19.
Biochim Biophys Acta ; 1860(10): 2137-47, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27233450

RESUMEN

BACKGROUND: Diabetic retinopathy is a leading cause of blindness. The objective was to design a novel fusion protein, Tat PTD-Endostatin-RGD, to treat retinal neovascularization via eye drops instead of traditional intravitreal injection trepapeutical methods. METHOD: The anti-angiogenesis ability was evaluated in vitro by chick embryo chorioallantoic membrane assay, wound healing assay and tube formation assay. Corneal barrier and blood-retina barrier were constructed in vitro to investigate the penetration ability of Tat PTD-Endostatin-RGD. Western blot was used to detect the integrin αvß3 expression level in rat retina microvascular endothelial cells which was stimulated by S-nitroso-N-acetylpenicillamine. The binding affinity of Tat PTD-Endostatin-RGD to integrin αvß3 was investigated by evaluating the penetration ability on blood-retina barriers treated with S-nitroso-N-acetylpenicillamine. The pharmacodynamics and efficacy analysis were further carried out in the oxygen-induced retinopathy model in vivo. In addition, the pharmacokinetic profile via eye drops was studied on a C57BL/6 mice model. RESULT: Tat PTD-Endostatin-RGD showed high anti-angiogenesis activity and high ability to penetrate these two barriers in vitro. The Western blot results indicated S-nitroso-N-acetylpenicillamine upregulated the expression level of integrin αvß3 in a dose-dependent manner. Tat PTD-Endostatin-RGD showed a high affinity to rat retina microvascular endothelial cells treated with S-nitroso-N-acetylpenicillamine. The results showed that Tat PTD-Endostatin-RGD could inhibit abnormal angiogenesis in retina via eye drops. CONCLUSION: Tat PTD-Endostatin-RGD showed high penetration ability through ocular barriers, bound specifically to integrin αvß3 and effectively inhibited the abnormal angiogenesis. GENERAL SIGNIFICANCE: Tat PTD-Endostatin-RGD represents a potent novel drug applied via eye drops for fundus oculi neovascularization diseases.


Asunto(s)
Retinopatía Diabética/tratamiento farmacológico , Endostatinas/administración & dosificación , Neovascularización Patológica/tratamiento farmacológico , Oligopéptidos/administración & dosificación , Proteínas Recombinantes de Fusión/administración & dosificación , Neovascularización Retiniana/tratamiento farmacológico , Animales , Barrera Hematorretinal/efectos de los fármacos , Embrión de Pollo , Membrana Corioalantoides/efectos de los fármacos , Retinopatía Diabética/genética , Retinopatía Diabética/patología , Endostatinas/metabolismo , Humanos , Integrina alfaVbeta3/biosíntesis , Integrina alfaVbeta3/genética , Ratones , Neovascularización Patológica/genética , Neovascularización Patológica/patología , Oligopéptidos/metabolismo , Soluciones Oftálmicas/administración & dosificación , Ratas , Proteínas Recombinantes de Fusión/metabolismo , Retina/efectos de los fármacos , Retina/patología , Neovascularización Retiniana/patología , Vasos Retinianos/efectos de los fármacos , Vasos Retinianos/patología , S-Nitroso-N-Acetilpenicilamina/metabolismo
20.
ACS Chem Biol ; 11(4): 850-63, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-26895482

RESUMEN

Cancer cells can be distinguished from normal cells by displaying aberrant levels and types of carbohydrate structures on their surfaces. These carbohydrate structures are known as tumor-associated carbohydrate antigens (TACAs). TACAs were considered as promising targets for the design of anticancer vaccines. Unfortunately, carbohydrates alone can only evoke poor immunogenicity because they are unable to induce T-cell-dependent immune responses, which is critical for cancer therapy. Moreover, immunotolerance and immunosuppression are easily induced by using natural occurring TACAs as antigens due to their endogenous property. This review summarizes the recent strategies to overcome these obstacles: (1) covalently coupling TACAs to proper carriers to improve immunogenicity, including clustered or multivalent conjugate vaccines, (2) coupling TACAs to T-cell peptide epitopes or the built-in adjuvant to form multicomponent glycoconjugate vaccines, and (3) developing vaccines based on chemically modified TACAs, which is combined with metabolic engineering of cancer cells.


Asunto(s)
Antígenos de Carbohidratos Asociados a Tumores/inmunología , Vacunas contra el Cáncer/inmunología , Secuencia de Carbohidratos , Humanos
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